Manufacture of lubricating oil



Patented Sept. 11, 1934 MANUFACTURE OF LUBRICATING ,OIL

corporation of Maine No Drawing. Application March 9, 1932, Serial No. 597,799

4 Claims. (01. 196-1) *This invention relates to improvements in the manufacture of petroleum lubricating oils; More particularly, the invention relates to improvements in controlof the colorand the bloom of v 5' petroleum lubricating oils. 4 r The color, by transmitted light; and the bloom, by reflected light, of petroleum lubricating oils' are dependent not only upon the character of the v crude petroleum from which the lubricating oil is derived but also uponthe'processing by which the lubricating'oil is derived. The market, how

ever, has tended to associate particular colors and blooms with particular characteristics. This tendency has-imposed an added burden on the 151 petroleum refiner in that it has subjected him to the necessity of controlling operations to'produce lubricating oils of particular color and bloom as well 'as to produce lubricatingoils having the required' characteristics asflubrica'nts. For exam- 201 pic, a distilled lubricating oil and a residual lubricating oil-having the samegener'al characteristics may be derived from the same crude. by difierent operations, the distilled product may be superior as a-lubricant to'the residual product, yet'the' distilled product may have a blue bloom whereas the residual product may have the green bloom required by the market for this particularproduct. This invention provides an improved control-"of the color and bloom of lubricating oils 3 0i which is independent of the process by which the lubricating oil is produced.

In one aspect, this invention provides a method of imparting the required color and bloom to lubricating oils by means of a dye. In this aspect the invention provides a dye which imparts the required color and bloom to the lubricating oil when used in small proportions and which, within the range of proportions necessary to secure the required color and bloom, does not impair 40. the properties of the petroleum lubricating oil with respect to emulsification or the stability of the oil, either during prolonged storage or during prolonged use, with respect to emulsification properties.

; According to the present invention, a residual tar produced by the cracking of petroleum stock at temperatures upwards of 775 F. is subjected to treatment with sulphuric acid and the sludge I formed as a consequence of this treatment is then 5&5 separated from the tar, the acid treated tar is then neutralized with an aqueous solution of sodium carbonate and the resulting aqueous solution is separated from the tar, any low boiling a, hydrocarbons present are then distilled from the acid treated and neutralized tar under conditions avoiding any substantial decomposition, "and the residuum from'this distillation isthen'blende'd. with thejpetroleum lubricating oil in'p'roportion not exceeding about3 by volume on the lubricat ing oil. Percentages approximating 1-l .5% are usually sufficient to impart the required'colorand' bloom to the lubricating oiL jThe residual tars produced by the cracking of petroleumstocks for the production of gasoline, by pressure distillation for example, are particularly usefu1 in carrying out the invention With the usual residual tars, the use of aboutBS-AO pounds'of 95 -100% sul phuric acid per barrel ofthe residual tar is ad-g. vantageous. The neutralization is, with adv'arr I tage, carriedout at a temperature approximating 150-209" 'F. The residuum" from the distillationi may, with advantage, be filtered, through an ab sorbent earth for example, beforeb-l'ending" with: the lubricating oil.

j I The invention will be'further illustratedby the following specific example of one op'eration emf bodying "the invention: 'A- residual tarhaving gravityof 1016 A. P. 1., produced in the pressure distillation of Mid-Continent gas oil at atemper tureof 800 850 F. for the production offgasoline; is agitated with 5-10 pounds'of 98%sulphuricacid per barrel of' tar at-a temperature of l10-130 Fbfor 5 -10 minute'siby'air blowin After settling for 2-6 hours, the -separated sludge is withdrawn. The tar is't'h'en agitated with 30 pounds of 98% sulphuric acid per barrel of tar at the same temperature by air blowing. The blowing is continued until a good separation, or break, of the sludge formed is. obtained without the addition of water. After settling for 2-6 hours the separated sludge is withdrawn. The tar is then blown with air for about2 hours, or until free from sulphur dioxide, any separated sludge is withdrawn and after settling for 4-5 hours-any further separated sludge is withdrawn. This acid treatment is carried out in the conventional agitator. Following the acid treatment, the tar is transferred to a so-called wash tank in which it is neutralized with 23-12% by volume of a 5-10 Be. aqueous solution of soda ash, the tem- ,100 perature ofv the mixture being brought to l70l80 F. and held until a separation, or break of the solution is obtained. From 15-30 hours is usually required. The aqueous solution is withdrawn and the acid-treated and neutralized tar is washed with hot water until it tests free of alkali when boiled with distilled water, phenolphthalein being used as the indicator. The acid-treated and neutralized tar is then .blown with air at a, temperature of I'm-180 F. until dry. Itis then transferred to a fire still and reduced with the use of suflicient steam to limit the maximum still temperature to about 500 F. to eliminate low boiling constituents. The residuum may have, for example, a dark green color, a flash point of 380-430 F., and a viscosity approximating 1000 at 100 (saybolt Universal). This residuum may be finished by filtration through '16-30 mesh Olmstead earth. This residuum product is the dye of the invention. It is blended with lubricating oils, including distilled lubricating oils, in proportions up to about 3% by volumeon lubricating oil. The volume of dye produced in carrying out the invention in this mannermay approximate, for example, 30-35% by volume on the residual tar subjected to treatment.

The invention is of special value and application in the manufacture of distilled petroleum lubricating oil. For example, the invention enables the conversion of distilled pale oils having a blue bloom to red oils having a green bloom. The invention is, however, of general application in control of color and bloom of lubricating oils, enabling the petroleum refiner to control the manufacturelof lubricating oils'to produce lubrieating oils having required characteristics as required color and bloom. v

lubricants and independently to control this manufacture to produce lubricating oils havin 'I claim:

'1. In the'manufacture of petroleum lubricating oils, the improvement which comprises subjecting a'residual tar produced by the cracking of a petroleum stock at temperatures upwards of 775 F.

to treatment with sulphuric acid and thereafter separating the sludge formed, neutralizing the acid treated tar after sludge separation with an aqueous solution of sodium carbonate and thereafter 'separatin'g'the aqueous solution,'distilling any low boiling hydrocarbons from the acid treated and neutralized tar under conditions avoiding any substantial decomposition, and thereafter blending the residuum with a lubricating oil in proportion not exceedingabout 3% by volume on the lubricating oil, thereby imparting a green bloom to the lubricating oil.

2. In the manufacture of petroleum lubricating oils, the improvement which comprises subjecting a residual tar produced by the cracking of a petroleum stock at temperatures upwards of 775 F.

to treatment with sulphuric acid and thereafter separating the sludge formed, neutralizing the acid treated tar after sludge separation with an aqueous solution of sodium carbonate and thereafter separating the aqueous solution, distilling any low boiling hydrocarbons from the acidtreated and neutralized tar under conditions avoiding any substantialdecomposition; filtering the residuum, and thereafter blending the residuum with a lubricating oil in proportion not exceeding about 3 by volume on the lubricating oil, thereby imparting agreen bloom to the lubricating oil. 3. In the manufacture of distilled petroleum lubricating oils, the improvement which comprises subjecting a residual tar produced by the 4. In the manufacture of petroleum lubricating oils, the improvement which comprises subjecting a residual tar produced by the cracking of a petroleum stock at temperatures upwards of 775 F. to treatment with about -40 pounds of 95-100% sulphuric acid per barrel of the residual tar and thereafter separating the sludge formed,

neutralizing the acid treated tar after sludge;

separation with an aqueous solution of sodium carbonate at a, temperature approximating l50.-200 Frand thereafter separating the aqueous solution, distillingany low boiling hydrocarbons from the acid treated and neutralized tar under conditions avoiding any substantial decomposition, and thereafter blending the residuum with a lubricating oil in proportion-not exceeding about 3% by volume onthe lubricating oil, thereby imparting a green bloom to the lubricating oil. v V p j CAREYFORBES SPENCER. 

